* syscalls.c (seteuid32): Return immediately if the program is not impersonated

and both uid and gid are original.
(setegid32): Return immediately if the new gid is the current egid.

2 files changed, 16 insertions, 11 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f2ab6b6..dadcec0 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+2002-07-01  Pierre Humblet  <pierre.humblet@ieee.org>
+
+	* syscalls.c (seteuid32): Return immediately if the program is not
+	impersonated and both uid and gid are original.
+	(setegid32): Return immediately if the new gid is the current egid.
+
 2002-07-01  Christopher Faylor  <cgf@redhat.com>
 
 	* syscalls.cc (seteuid32): Fix incorrect placement of Pierre's patch
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 438cb77..a66b69e 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -617,7 +617,7 @@ _link (const char *a, const char *b)
   sigframe thisframe (mainthread);
   path_conv real_b (b, PC_SYM_NOFOLLOW | PC_FULL);
   path_conv real_a (a, PC_SYM_NOFOLLOW | PC_FULL);
-  
+
   if (real_a.error)
     {
       set_errno (real_a.error);
@@ -1955,11 +1955,16 @@ mkfifo (const char *_path, mode_t mode)
 extern "C" int
 seteuid32 (__uid32_t uid)
 {
-  if (!wincap.has_security ()) return 0;
 
-  if (uid == ILLEGAL_UID)
+  debug_printf ("uid: %d myself->gid: %d", uid, myself->gid);
+
+  if (!wincap.has_security ()
+      || (!cygheap->user.issetuid ()
+	  && uid == myself->uid
+	  && myself->gid == cygheap->user.orig_gid)
+      || uid == ILLEGAL_UID)
     {
-      debug_printf ("new euid == illegal euid, nothing happens");
+      debug_printf ("Nothing happens");
       return 0;
     }
 
@@ -1971,8 +1976,6 @@ seteuid32 (__uid32_t uid)
   struct passwd * pw_new;
   PSID origpsid, psid2 = NO_SID;
 
-  debug_printf ("uid: %d myself->gid: %d", uid, myself->gid);
-
   pw_new = getpwuid32 (uid);
   if (!usersid.getfrompw (pw_new) ||
       (!pgrpsid.getfromgr (getgrgid32 (myself->gid))))
@@ -2104,11 +2107,6 @@ seteuid32 (__uid32_t uid)
   if (cygheap->user.issetuid ()
        && !ImpersonateLoggedOnUser (cygheap->user.token))
     system_printf ("Impersonating in seteuid failed: %E");
-  if (uid == myself->uid)
-    {
-      syscall_printf ("special case, returning 0");
-      return 0;
-    }
   return -1;
 }
 
@@ -2140,6 +2138,7 @@ extern "C" int
 setegid32 (__gid32_t gid)
 {
   if ((!wincap.has_security ()) ||
+      (gid == myself->gid) ||
       (gid == ILLEGAL_GID))
     return 0;